A major redesign of an existing clinical trials computer program was undertaken. The objective was flexibility. Consequently, an investigator may designate particular dependent variables such as net increment DMFS, initial normal, erupting teeth, on a study as opposed to receiving total standard information which is not all needed or wanted. The PL/I program also allows the statistical output to be shown for many classifications of individuals such as age, sex, race, school, etc., at one time. Maximum efficiency of computer time and minimal input on user's part are the current objectives.